Introduction

Music Synthesiser turns the BBC Micro into a four channel sequencer, with three instrument channels and one effects channel. Facilities include:

1. Entry and modification of musical pieces
2. Defining up to 16 instructions (only four available on OS 0.1)
3. Saving and loading entire pieces on tape or disc
4. Playing pieces either straight through or using a verse structure

You are well advised to read the BBC manual's section on ENVELOPE before using Music Synthesiser.

Using The Menu

Music Synthesiser is a menu-based program. Each menu has a list of options; the first letter of which must be pressed to select the appropriate option. Note: Menus only accept capital letters. For example, in the main menu the Play option is selected by pressing "P". Invalid options are ignored.

Out of range numeric inputs are responded to by a short beep.

Some questions in this program ask "Are you sure?". These questions must be answered YES (RETURN). All other responses are taken as no.

Getting Started

If you are using a tape system, type:

CHAIN"" (RETURN)

The program should respond:

600 Notes available, O.K. (Y/N) ?

For initial use type Y. Typing N will make an extra 1,024 notes available, but disables the Graph feature (See Edit Envelope section).

If you are using a disk system, type:

CHAIN"MUSIC" (RETURN)

A similar message to the above will appear, offering fewer notes.

Main Menu Options

The main menu offers:

D(isplay), E(dit), P(lay), L(oad), S(ave)

1. Display

Displays lists of all the names of the instruments which you have entered, and also indicates the overall piece parameters as:

1. the length of the piece (X notes in sequence)
2. the maximum length available (X notes available)
3. the playing speed (X 1/100th seconds per note)
4. the note length (X 1/100ths second before release (See BBC manual ENVELOPE chapter))

2. Edit

This gives the Edit sub-menu. Edit is used to create pieces and instruments. The four sub-menu options are:

2a. Edit Envelope

This option allows creation of instrument envelopes. The question "which envelope?" is given. If you have an old machine with OS Eprom 0.1, you should enter a number from 1 to 4, otherwise 1 to 16. (You may check which OS you have by typing *FX0)

A display of envelope parameters is then given, with a red function key menu at the bottom of the screen.

The parameters in the display are the same as those described in the BBC manual ENVELOPE section.

To set up the most simple sound type the following (each followed by RETURN):

8, 126, 12, 126, 11, -1

This sets up an attack rate of 126 (sharp attack), attack level of 126 (loud) and a release rate of -1 (slow release).

Pressing f0 will sample the sound you have created.

Pressing f2 will give a graph (unless you typed N to the question at the start of the program, in which case this facility is not available). The green line represents the volume, and blue the pitch. Time is measured across the top in centiseconds. The line in the centre indicates the start of the release Phase. You may of course experiment as much as you wish with the envelope parameters, examining their effect on the sound and its graph, until you have created a sound which you require for an instrument in your piece.

If you create a sound which never fades away, the Quiet button (f2) will stop the sound.

f3 allows you to name your instrument.

f4 plays a sample note on the noise channel (Channel 0). You should first set the appropriate sample frequency for the effect required using the Note (f5) key (See sound chapter of BBC manual for details of noise effects.)

f5 allows you to select the sample frequency for the Sound and Noise buttons.

Press RETURN to end the edit.

Once you have created a sound, you may use it in your piece. You may, of course, re-edit the envelope to modify your creation.

2b. Edit Channel

This option allows you to enter notes into the sound channels (or parts) of the piece. The question "Which channel?" is given. You should reply 0, 1, 2 or 3 (RETURN) (Channel 0 gives special effects only)

The Channel Editor Display

At the top line of the screen is an indication of the current edit channel and its initially selected instrument. The red keys f0, f1, f2 and f3 can be used to change between channels. Notes of the selected channel are shown in green. The current edit note flashes. The INIT button (f4) is used to change the initial instrument for the selected channel.

Inserting And Editing Notes And Directives

To enter a note at the current (flashing) note, type in the following format:

note name/optional # or $ (for sharp or flat)/octave number. Eg. C#4 means C sharp of octave 4

The octave number changes as the alphabet wraps round i.e. A2 follows G#1, A3 follows G#2, etc.

The lowest note available is A#0 (or just A#, the 0 may be omitted). The highest is D5.

Whenever a note is entered, it is also played on the initial instrument.

The other directives are available by typing the initial letter followed by RETURN. These are:

S - Silent. Inserts a gap, which will usually allow the previous note to sound for longer.

I - Instrument. Allows the playing instrument to change to a new one partway through the piece.

R - Repeat a section. This allows a section to be inserted (rather like a subroutine) after the current note. The R directive need only be put in any one channel to affect all four channels.

All directives take one note time to execute, and may be used alongside ordinary notes in the other channels.

The editor will also accept a number; this moves the pointer to the desired note number. After entering a note or directive, the pointer will move onto the next note.

Functions f5 to f9

f5 allows deletion of any number of notes, starting at the current note. All notes below are shifted up.

f6 allows insertion of any number of notes at the pointer position. A gap of silence is created and all notes from the pointer onwards are shifted down.

f7 Clear channel. This allows all the notes of the current edit channel to be set to silent.

f8 Transpose. This allows the selected channel to be transposed up or down by any number of semitones (enter a negative number to transpose down). Be careful that your transposition does not move any notes outside the range A# to D5.

f9 End. Used to end channel edit mode. This can also be done by entering 0 (RETURN) (if you are paranoid about hitting the BREAK key).

2c. Edit All

This option is for setting up the sequence length and playing speed.

2d. Edit Section

This allows the creation of sections (which may be used for verses/choruses, etc). The sections may be used with the R directive (see Edit Channel) or in the play section command. You are advised to keep a note of which sections you have used, where they start and end, and what they represent.

Pressing RETURN will exit from edit mode.

3. Play

The play sub-menu offers two options.

3a. Play All

This pplays the piece through from note 1.

3b. Play Sections

This plays a list of sections. e.g. if you defined Section 1 as notes 1 to 64 to represent a verse, and Section 2 as notes 65 to 96 to represent a chorus, then entering the following: (Each followed by RETURN):

5	1	2	1	2	2

will play five sections, first 1 (verse notes 1 to 64) then 2 (chorus notes 65 to 96) then the verse then the chorus, then another chorus.

Play may be aborted by hitting the Escape key.

4. Load And Save

Load and save are used to keep tape records of your music. Simply type:

S YES (RETURN) Name-of-piece (RETURN)

to save your piece, and

L YES (RETURN) Name-of-piece (RETURN)

to load your piece back.

Note: If you are using a disc system the message "Save on tape" is still issued, although the program will work with the discs.

If you have a copy of the faulty Operating System (Version 0.1), you may have some problems with load and save, because of bugs in the Operating System. Please ask Acorn to replace your faulty ROM.

You should use a recorder with motor control if at all possible.

Instructions For Auto-Composer

To load, type CHAIN"" (RETURN)

Auto-Composer is an automatic tune-generating program. The following parameters are required:

1. Speed in 100th seconds per note
2. Number of notes in a bar
3. Syncapation
4. Syncapation note

The first two of these are self-explanatory. Auto-Composer normally plays notes at equal intervals (if you enter 0 to both of questions 3 and 4). Syncapation X at note Y, moves the Yth note of each bar forward by X/100 seconds.

Chord Weights

Auto-Composer writes tunes by selecting one of 24 chords, then playing a few bars based upon that chord. The chord weights are probabilities that particular chords will be played next. For a reasonable composition, select only a few chords (4, 5 or 6, say) and weight them with numbers in the range 1 to 20 (just type RETURN to unwanted chords).

Auto-Composer will occasionally remember lead times and re-use them.